Chess: Add serialization of moves and squares

Author: https://github.com/petelliott
Commit: https://github.com/SerenityOS/serenity/commit/ffece9cfba9
Pull-request: https://github.com/SerenityOS/serenity/pull/3214
Issue: https://github.com/SerenityOS/serenity/issues/3171
Issue: https://github.com/SerenityOS/serenity/issues/3187
Reviewed-by: https://github.com/Dexesttp
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/awesomekling

Games/Chess/Chess.cpp

@@ -27,9 +27,30 @@
 #include "Chess.h"
 #include <AK/Assertions.h>
 #include <AK/LogStream.h>
+#include <AK/String.h>
+#include <AK/StringBuilder.h>
 #include <AK/Vector.h>
 #include <stdlib.h>
 
+String Chess::char_for_piece(Chess::Type type)
+{
+    switch (type) {
+    case Type::Knight:
+        return "N";
+    case Type::Bishop:
+        return "B";
+    case Type::Rook:
+        return "R";
+    case Type::Queen:
+        return "Q";
+    case Type::King:
+        return "K";
+    case Type::Pawn:
+    default:
+        return "";
+    }
+}
+
 Chess::Square::Square(const StringView& name)
 {
     ASSERT(name.length() == 2);
@@ -51,6 +72,23 @@ Chess::Square::Square(const StringView& name)
     }
 }
 
+String Chess::Square::to_algebraic() const
+{
+    StringBuilder builder;
+    builder.append(file - 'a');
+    builder.append(rank - '1');
+    return builder.build();
+}
+
+String Chess::Move::to_long_algebraic() const
+{
+    StringBuilder builder;
+    builder.append(from.to_algebraic());
+    builder.append(to.to_algebraic());
+    builder.append(char_for_piece(promote_to).to_lowercase());
+    return builder.build();
+}
+
 Chess::Chess()
 {
     // Fill empty spaces.

Games/Chess/Chess.h

@@ -43,6 +43,7 @@ public:
         King,
         None,
     };
+    static String char_for_piece(Type type);
 
     enum class Colour {
         White,
@@ -55,6 +56,7 @@ public:
         Colour colour;
         Type type;
         bool operator==(const Piece& other) const { return colour == other.colour && type == other.type; }
+
     };
     static constexpr Piece EmptyPiece = { Colour::None, Type::None };
 
@@ -84,6 +86,7 @@ public:
 
         bool in_bounds() const { return rank < 8 && file < 8; }
         bool is_light() const { return (rank % 2) != (file % 2); }
+        String to_algebraic() const;
     };
 
     struct Move {
@@ -98,6 +101,8 @@ public:
         {
         }
         bool operator==(const Move& other) const { return from == other.from && to == other.to && promote_to == other.promote_to; }
+
+        String to_long_algebraic() const;
     };
 
     Chess();